System and method for material density distribution survey based on cosmic muon detection

Abstract

Provided herein is a system and method designed for measuring and recording, in three-dimensional space, an attenuation of cosmic-ray induced muon particle flux through a material. The attenuation of the said muons determines density variations in the said material in terms of their density, depth, shape and size. The muon data may be combined with various other data types. The passing muons are detected and recorded by one or a plurality of muon detection apparatus designed to be robust and shock resistant. If needed, each individual muon detection apparatus may be controlled remotely or automatically. The muon detection system may be powered by an energy storage device that may be recharged using renewable energy, aggregate or electric grid. The invention comprises methods steps allowing density characterisation of the material in various dimensions, including those over time.

The invention claimed is: 
     
       1. A muon detection system for investigating density variations of materials, the muon detection system comprises:
 at least one muon detection apparatus, which muon detection apparatus comprises a scintillation detector part, matrix detector and position and orientation apparatus, 
 which muon detection apparatus is configured to:
 detect in the scintillation detector part emitted photons by the matrix detector, which in the scintillation detector part emitted photons result from cosmic-ray induced muon particles passing via a plurality of intersecting muon trajectories through the material situated in a subsurface measurement volume of the muon detection apparatus; 
 which position and orientation apparatus is configured to:
 determine the position and orientation of the muon detection apparatus and produce position and orientation data of the muon detection apparatus; 
 
 
 wherein the muon detection system further comprises:
 at least one decentralized DAQ system comprising a surface part and a detector part, said DAQ system configured to:
 receive operational commands; 
 process the photon signals of detected photons into the form of a muon recording; 
 send the position and orientation data and the muon recording; and 
 send operational parameters from the surface part of the DAQ system to the detector part of the DAQ system; 
 
 at least one supporting system, configured to:
 position at least one muon detection apparatus to receive the muon recording from the subsurface measurement volume; 
 
 a processing unit, configured to:
 send operational commands; 
 collect at least one muon recording; 
 collect the position and orientation data of at least one muon detection apparatus; 
 extract material densities from the subsurface measurement volume by utilising at least one muon recording; and 
 merge extracted material densities from the subsurface measurement volume into a density distribution map. 
 
 
 
     
     
       2. The muon detection system according to  claim 1 , wherein the supporting system is further configured to reposition at least one muon detection apparatus. 
     
     
       3. The muon detection system according to  claim 1 , wherein the muon detection system further comprises the electrical energy storage device, configured to deliver electricity for at least one device selected from the muon detection apparatus, DAQ system and communication hub device. 
     
     
       4. The muon detection system according to  claim 1 , wherein the muon detection system further comprises at least one server, configured to be connected via a communication network to the communication hub device. 
     
     
       5. The muon detection system according to  claim 4 , wherein the server is the processing unit. 
     
     
       6. The muon detection system according to  claim 4 , wherein the muon detection system further comprises a remote computer, configured to be connected to at least one server via the communication network or local connection means, which remote computer is the processing unit. 
     
     
       7. The muon detection system according to  claim 1 , wherein the muon detection system further comprises at least one communication hub device, configured to transfer data, which data comprises any of the muon recording, operational commands, operational parameters, position and orientation data and operational variables between at least one muon detection apparatus and the processing unit. 
     
     
       8. The muon detection system according to  claim 1 , wherein the communication hub device further comprises a local computer, which local computer is the processing unit. 
     
     
       9. The muon detection system according to  claim 1 , wherein the muon detection system further comprises a weather station, configured to be connected via the communication hub device to the processing unit, which weather station is configured to produce meteorological measurement data from the region of the muon detection system. 
     
     
       10. The muon detection system according to  claim 9 , wherein the meteorological measurement data comprises at least one measurement selected from temperature, wind direction, wind speed, gust speed, atmospheric pressure, relative humidity, cloud amount, snow depth, sunshine duration, ultraviolet irradiance measurement and air quality observations. 
     
     
       11. The muon detection system according to  claim 9 , wherein the processing unit is further configured to combine the meteorological measurement data with the muon recording. 
     
     
       12. The muon detection system according to  claim 1 , wherein the scintillation detector part comprises a plurality of optically separated scintillation bars, which scintillation bars are equipped with at least one matrix detector each. 
     
     
       13. The muon detection system according to  claim 1 , wherein the scintillation detector part comprises of scintillation material mounted in an optically isolating matrix framework, in which each compartment is equipped with at least one matrix detector. 
     
     
       14. The muon detection system according to  claim 1 , wherein the muon detection apparatus is configured to fit in a borehole of 100 mm or less in diameter. 
     
     
       15. The muon detection system according to  claim 1 , wherein the electrical energy storage device is further configured to be recharged by at least one energy source selected from a solar panel, windmill, hydroelectric power generator or aggregate. 
     
     
       16. The muon detection system according to  claim 1 , wherein the supporting system further comprises a detector connecting cable, which detector connecting cable encloses:
 a communication cable, configured to transfer data between the surface part of the DAQ system and connected muon detection apparatus and deliver electricity to the connected muon detection apparatus; and 
 a mechanical cable, configured to position the connected muon detection apparatus. 
 
     
     
       17. The muon detection system according to  claim 16 , wherein the muon detection system further comprises a plurality of muon detection apparatus, interconnected through the detector connecting cable serially to each other. 
     
     
       18. The muon detection system according to  claim 1 , wherein the muon detection apparatus further comprises a first communication device, configured to transfer data between the DAQ system and communication hub device. 
     
     
       19. The muon detection system according to  claim 1 , wherein at least one muon detection apparatus further comprises a second communication device, configured to collect muon recordings from the interconnected muon detection apparatus and transfer the data between the second communication device and the communication hub device. 
     
     
       20. A method for investigating material densities with a muon detection system, the method comprising method steps:
 activating a muon detection apparatus by sending operational commands by using a processing unit; 
 receiving the operational commands by using a decentralized DAQ system comprising a surface part and a detector part; 
 sending operational parameters from the surface part of the DAQ system to the detector part of the DAQ system; 
 detecting in a muon detection apparatus located scintillation detector part emitted photons with a matrix detector, which emitted photons result from cosmic-ray induced muon particles passing via a plurality of intersecting muon trajectories through the material situated in the subsurface measurement volume of the muon detection apparatus; 
 processing the signals of detected photons into the form of a muon recording by using the DAQ system; 
 determining the position and orientation of the muon detection apparatus and producing position and orientation data of the muon detection apparatus by using a position and orientation apparatus; 
 sending the position and orientation data and muon recording from at least one muon detection apparatus via a communication hub device to the processing unit; and 
 processing at least one muon recording by using the processing unit, which processing steps comprise:
 collecting at least one muon recording; 
 collecting the position and orientation data of at least one muon detection apparatus; 
 extracting density variations from the subsurface measurement volume by utilising at least one muon recording and position and orientation data of at least one muon detection apparatus; and 
 merging the extracted density variations from the subsurface measurement volume into a density distribution map. 
 
 
     
     
       21. The method according to  claim 20 , wherein sending operational parameters of the muon detection apparatus by using the DAQ system to the processing unit. 
     
     
       22. The method according to  claim 20 , wherein transfer data, which data comprising any of the muon recording, operational parameters, and position and orientation data from at least one muon detection apparatus via the communication hub device to at least one server, wherein the transferred data are processed into the density distribution map. 
     
     
       23. The method according to  claim 20 , wherein collecting meteorological measurement data from a weather station via the communication hub device to the processing unit, which meteorological measurement data comprises at least one measurement selected from temperature, wind direction, wind speed, gust speed, atmospheric pressure, relative humidity, cloud amount, snow depth, sunshine duration, ultraviolet irradiance measurement and air quality observations. 
     
     
       24. The method according to  claim 20 , wherein combining the meteorological measurement data with the muon recordings by using the processing unit.